Many therapeutic proteins such as, for example, antibodies may be administered via subcutaneous injection. This injection pathway requires a high protein concentration in the final solution to be injected (Shire et al., J Pharm Science, 2004; 93(6): 1390-1402; Roskos et al., Drug Devel Res, 2004; 61(3): 108-120). Achieving the high protein concentration necessary for subcutaneous delivery can be problematic.